Considering the relevance of determining HER2 status in metastatic GOC for optimal treatment selection, the limitations linked to sample adequacy and methodology (type of test) used and the need for rapid HER2 report, we aimed to develop and validate a nomogram, based on easily accessible clinical or pathologic characteristics, which is able to anticipate the probability of harbouring a HER2 positive disease before direct tumour assessment by IHC and ISH. This evidence concerns the gene ERBB2 and neoplasm.